Fundamentals · Published July 29, 2026

Financial Ratios Explained with 40 Years of Apple Data

By Slowio

A financial ratio is a single division — operating income over revenue, net income over equity — but one value in isolation is nearly meaningless. A 20% margin can be a triumph or a decline depending entirely on the path that led there. The information lives in the trajectory: forty fiscal years of the same ratio, computed the same way, side by side.

Computing that by hand means pulling forty annual reports per company, which is why almost nobody does it. Below, what the full ratio history looks like when it is already computed — Apple’s four decades of margins and returns on capital, exactly as Slowio’s ratios page draws them.

Charts and figures are computed from Slowio’s data snapshot as of 2026-07-29 and are refreshed when the article is next updated.
Feature spotlight · Financial ratios

Every ratio, already computed

Sizing up a business usually means computing the same ratios over and over — price against earnings and book value, margins, returns on capital, debt against equity — for every fiscal year, from statements scattered across decades of annual reports. The ratios page does that arithmetic in advance: valuation, profitability and balance-sheet ratios, computed per fiscal year for each of the thousands of companies Slowio follows, and already charted.

Here is what that looks like for Apple Inc. — 41 fiscal years of ratio history, two of the charts the ratios page opens with:

Bar chart: Apple Inc. operating margin and net income margin by fiscal year, 1985-2025
Apple Inc. — operating and net income margin by fiscal year (%), the first chart on the ratios page.
Bar chart: Apple Inc. return on equity and return on assets by fiscal year, 1985-2025
Apple Inc. — return on equity and return on assets by fiscal year (%): how much profit each unit of capital produced.

The history is the story: operating margin went from 8% in 1985, through -15% in 1997, to 32% in 2025 — and every reading in between is one bar on the chart. Under the charts sit the latest numbers themselves. Apple Inc., FY 2025:

AAPL.US · Apple Inc.
Technology · Consumer Electronics · USA
45.6
P/E
69.2
Price / Book
51.7
Price / FCF
32.0%
Oper. margin
26.9%
Net margin
151.9%
ROE
31.2%
ROA
0.79
Tot. liab. / assets
1.06
Long debt / equity

Every figure is computed the same way for every company, so a ratio read here can be lined up against any other company — or against its own value ten, twenty or forty years ago. Swap the ticker in the page URL, or use the search box, to see any other company the same way.

And one step further — the Correlations tab puts Apple Inc. next to the four big asset classes: US equities (SPY.US), long-term Treasuries (TLT.US), inflation-linked Treasuries (TIP.US) and gold (GLD.US). Over 180-day returns since 2005, the tightest link is AAPL.US–SPY.US at +0.52; against long-term Treasuries it drops to +0.09.

Chart matrix: pairwise 180-day return scatters, histograms and correlation values for AAPL.US, SPY, TLT, TIP and GLD
Every pair — scatter below the diagonal, return histograms on it, correlation above: 5,275 overlapping 180-day observations, 2005–2026, each series in its listing currency.
Scatter chart with marginal histograms: AAPL.US versus SPY.US 180-day returns with regression line
The tightest pair up close — AAPL.US versus SPY.US — with the return distributions on the margins; the dashed line is the fitted trend.

What weight does Apple Inc. get in that mix? The Rebalance & Opt. tab’s Max Diversification objective — the weights that damp how much the five move together — answers with numbers: the optimizer gives AAPL.US a 2% seat, though the diversification ratio barely moves (1.72 versus 1.72 without it).

Bar chart: Max Diversification weights for AAPL.US and the four asset-class ETFs
The maximum-diversification mix, computed by the app’s optimizer on the same 180-day returns (diversification ratio: how much less the whole moves than its parts — higher is more diversified). A hypothetical, educational exercise — not an allocation recommendation.
Open the ratios page →

Slowio is an educational research tool, not financial advice. Figures are computed from Slowio’s data snapshot at build time and may not reflect the latest market data — nothing in this email is a recommendation to buy or sell any security. Do your own research.

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